A. Field of the Invention
The present invention relates to a bending press of the kind having a worktable and a lower and upper tool and sometimes known as a "press brake". More particularly the invention relates to a bending press of this kind in which the lower tool is supported in an elastically resilient manner.
B. The Description of the Prior Art
The present applicants have already proposed using an elastic substrate or an oil cushion for the support, and in this connection we have put forward specific proposals as to how the accuracy of the working operation of the press can be improved. More particularly, provision is made for compensating automatically for any deformation of those elements of the bending press which participate primarily in the pressing operation. One proposal, for this purpose, provides for the use of a worktable having a table plate which rests on a supporting element which corresponds to the length of the table plate and which is mounted so as to be vertically displaceable in a base part so as to rest on an oil cushion. If the workpiece to be processed is shorter than the available length of the worktable, then the workpiece is too severely pressed at the ends and inaccuracies arise at the ends. More precise workpiece processing is possible with a bending press in which the tool itself, which is supported in an elastically-resilient manner, or its support, is formed from a number of sections which are arranged side-by-side so as to be vertically displaceable independently of one another, in such a way that, under load, only those sections on which the workpiece rests directly or indirectly are shifted against the action of the elastic substrate. Examples of these prior art proposals are found in U.S. Pat. No. 4,014,204.